Bottom Line:
However, the effects of single short-term fasting on brain tissue or behavioral activity patterns remain unclear.The brain weight did not change by a fast, and brain atrophy was not observed.However, it is interesting that the results of this study suggest that single short-term fasting has an effect on encephalic neuropoiesis.

ABSTRACTIn humans, emaciation from long-term dietary deficiencies, such as anorexia, reportedly increases physical activity and brain atrophy. However, the effects of single short-term fasting on brain tissue or behavioral activity patterns remain unclear. To clarify the impact of malnutrition on brain function, we conducted a single short-term fasting study as an anorexia model using male adult mice and determined if changes occurred in migratory behavior as an expression of brain function and in brain tissue structure. Sixteen-week-old C57BL/6J male mice were divided into either the fasted group or the control group. Experiments were conducted in a fixed indoor environment. We examined the effects of fasting on the number of nerve cells, structural changes in the myelin and axon density, and brain atrophy. For behavior observation, the amount of food and water consumed, ingestion time, and the pattern of movement were measured using a time-recording system. The fasted mice showed a significant increase in physical activity and their rhythm of movement was disturbed. Since the brain was in an abnormal state after fasting, mice that were normally active during the night became active regardless of day or night and performed strenuous exercise at a high frequency. The brain weight did not change by a fast, and brain atrophy was not observed. Although no textural change was apparent by fasting, the neuronal neogenesis in the subventricular zone and hippocampus was inhibited, causing disorder of the brain function. A clear association between the suppression of encephalic neuropoiesis and overactivity was not established. However, it is interesting that the results of this study suggest that single short-term fasting has an effect on encephalic neuropoiesis.

pone-0080085-g004: Movement behavioral patterns and running distance of mice in the second period given ad libitum intake of food and water.(A) An example of the movement behavioral pattern of a mouse in the second period. (B) Running distance in a dark and light phase in the second period. Values are Mean ± S.D. (n = 10). P < 0.001, significantly different from the dark phase value.

Mentions:
The mice showed a typical pattern for nocturnal movement; they were inactive during the light phase and active during the dark phase (Figure 4-A). A similar pattern was found in all individuals of the 2 groups. The mice ran a distance of approximately 100 m/12 hours during the dark phase and 30 m/12 hours during the light phase (Figure 4-B). For the fasted group, the movement pattern increased in activity and became more pronounced over the second and third day of fasting. (Figure 5-A). Running distance significantly increased to approximately 1200 m/day in the fasted group compared to 130 m/day in the control group (Figure 5-B).

pone-0080085-g004: Movement behavioral patterns and running distance of mice in the second period given ad libitum intake of food and water.(A) An example of the movement behavioral pattern of a mouse in the second period. (B) Running distance in a dark and light phase in the second period. Values are Mean ± S.D. (n = 10). P < 0.001, significantly different from the dark phase value.

Mentions:
The mice showed a typical pattern for nocturnal movement; they were inactive during the light phase and active during the dark phase (Figure 4-A). A similar pattern was found in all individuals of the 2 groups. The mice ran a distance of approximately 100 m/12 hours during the dark phase and 30 m/12 hours during the light phase (Figure 4-B). For the fasted group, the movement pattern increased in activity and became more pronounced over the second and third day of fasting. (Figure 5-A). Running distance significantly increased to approximately 1200 m/day in the fasted group compared to 130 m/day in the control group (Figure 5-B).

Bottom Line:
However, the effects of single short-term fasting on brain tissue or behavioral activity patterns remain unclear.The brain weight did not change by a fast, and brain atrophy was not observed.However, it is interesting that the results of this study suggest that single short-term fasting has an effect on encephalic neuropoiesis.

ABSTRACTIn humans, emaciation from long-term dietary deficiencies, such as anorexia, reportedly increases physical activity and brain atrophy. However, the effects of single short-term fasting on brain tissue or behavioral activity patterns remain unclear. To clarify the impact of malnutrition on brain function, we conducted a single short-term fasting study as an anorexia model using male adult mice and determined if changes occurred in migratory behavior as an expression of brain function and in brain tissue structure. Sixteen-week-old C57BL/6J male mice were divided into either the fasted group or the control group. Experiments were conducted in a fixed indoor environment. We examined the effects of fasting on the number of nerve cells, structural changes in the myelin and axon density, and brain atrophy. For behavior observation, the amount of food and water consumed, ingestion time, and the pattern of movement were measured using a time-recording system. The fasted mice showed a significant increase in physical activity and their rhythm of movement was disturbed. Since the brain was in an abnormal state after fasting, mice that were normally active during the night became active regardless of day or night and performed strenuous exercise at a high frequency. The brain weight did not change by a fast, and brain atrophy was not observed. Although no textural change was apparent by fasting, the neuronal neogenesis in the subventricular zone and hippocampus was inhibited, causing disorder of the brain function. A clear association between the suppression of encephalic neuropoiesis and overactivity was not established. However, it is interesting that the results of this study suggest that single short-term fasting has an effect on encephalic neuropoiesis.